/**
 * @param {string} sentence
 * @return {boolean}
 */
var isCircularSentence = function (sentence) {
  let len  = sentence.length
  if(sentence[len-1]!=sentence[0]) return false
  for(let i=0;i<navigator;i++){
    if(sentence[i]==' ' && sentence[i-1]!=sentence[i+1]) return false
  }

  return true
};